In the prior art, numerous devices having angled or movable portions have been proposed to facilitate device manipulation in various medical procedures. U.S. Pat. No. 4,169,984 to Parisi discloses an ultrasonic probe assembly for use in surgical procedures. The ultrasonic probe includes an angled tip portion as best seen in FIG. 2. However, the tip of Parisi does not include structure to permit movement thereof during surgical procedures.
U.S. Pat. No. 4,210,146 to Banko discloses a surgical instrument with a bendable blade. The blade is designed to move with respect to an opening in the instrument tip to make a shearing action to cut tissue which enters the opening. The blade is formed in a manner so that, as it reciprocates into a tapered portion of the distal end tube, it will bend to conform to the shape of the tapered portion of the tube to provide continuous contact and improve cutting action. The surgical instrument of Banko does not teach or suggest a flexible tip the shape of which may be remotely altered to access different surgical sites.
U.S. Pat. No. 4,445,509 to Auth discloses a rotating cutting tool having spirally shaped cutting flutes with different cutting properties. The tool is driven from outside the tool body by means of a flexible drive shaft. The tool of Auth is designed to be inserted into a human vascular network to remove plaque deposits.
U.S. Pat. No. 4,473,077 to Noiles et al. discloses a surgical stapler apparatus having a flexible shaft. The apparatus includes structure which greatly reduces or essentially eliminates the tendency of the shaft assembly to revert to its straight condition during transmittal of longitudinal forces during stapling.
U.S. Pat. No. 4,672,964 to Dee et al. discloses a scalpel having a universally adjustable blade mounted to the scalpel handle for selective positioning. The scalpel includes structure which permits rotation of the blade about the axis of the handle as well as angular positioning with respect thereto. However, the scalpel assembly does not include means which permits flexing or bending of the scalpel or scalpel assembly during use.
U.S. Pat. No. 3,847,154 to Nordin discloses a surgical drill having an angular housing which is particularly useful where it is desired to reach very inaccessible areas in the body during a sensitive operation. However, the angular housing of the surgical drill disclosed in the Nordin patent is not flexible or adjustable.
Australian Patent Specification Number 57321 to Pericic discloses an oscillating surgical knife which has specific applications to eye surgery. The oscillating surgical knife, in one embodiment, includes a chuck which permits angular displacement of the blade in the direction of oscillation thereby allowing the blade to be located at angles to enable the blade to reach a position which may otherwise be difficult or impossible. However, the oscillating surgical knife of Pericic does not include structure or means to permit the knife to be flexibly steered to access difficult to reach areas.
U.S. Pat. No. 1,741,740 to Sederholm et al., Soviet Union Patent Number 992044 to Crimea Medical Institute and East German Patent Number 203,230 to Streubel disclose surgical cutting instruments having adjustable blades therewith. None of these documents disclose a flexible and steerable aspiration tip for use in microsurgery.
In the field of cataract surgery, the goal of the surgery is the removal and anatomical replacement of an original, clouded lens with an optically clear intraocular lens using a small incision as well as a minimum of trauma to the surgical site. Current techniques being used to effect cataract surgery include extra capsular cataract extraction (ECCE) or endocapsular phacoemulsification (ECPE). As part of these techniques, a small gauge irrigation/aspiration tip is used to remove any residual cortex and epithelium adjacent the capsular bag.
With reference to FIGS. 1 and 2, examples of cataract surgery techniques are depicted to illustrate deficiencies in prior art surgical instruments. FIG. 1 illustrates a sectional view of an eye 100 including a cornea 103, sclera 105, iris 107 and capsular bag 111. During extracapsular cataract extraction, a straight and rigid irrigation/aspiration instrument 113 having a tip portion 115 is inserted into the eye through the limbal incision 117. Peripheral cortex is easily engaged by the irrigation/aspiration tip 115 at the location directly opposite the incision designated by reference numeral 119. However, as can be seen in FIG. 1, the cortex directly under the iris 107 directly below the incision 121 is difficult to access when using a straight and rigid irrigation/aspiration tip.
In an effort to remove the cortex from the location directly below the incision, several complicated and difficult manuevers using the straight and rigid irrigation/aspiration tip must be employed. In one manuever, the iris is drawn out of the wound using smooth forceps while the irrigation/aspiration tip is inserted and exposed cortex is engaged by aspiration. These manuevers are difficult to execute since visualization of the underlying cortex through the iris is impossible and, in certain cases with a constricted iris, even more difficult to perform. As a result of these different manuevers, excess trauma may result in the surrounding ocular tissue including exposing and/or weakening of the zonules 120, or enlargement of the limbal incision with subsequent possible collapse of the anterior chamber 109.
In response to these deficiencies in the prior art, irrigation/aspiration tips have been proposed having an angled or bent configuration. With reference now to FIG. 2, an irrigation/aspiration tip 123 is shown inserted through the limbal incision 117 and including an angled tip portion 125. Using the angled tip 125, cortex may be easily removed from the 12 o'clock position 121. However, engagement and removal of cortex directly under the iris at the 6 o'clock position 119 becomes difficult using the angled tip 125.
To achieve cortex removal from both the 6 o'clock position 119 and the 12 o'clock position 121, both the straight and rigid irrigation/aspiration tip 113 and the angled tip 123 must be used during the surgical procedure. Using both surgical instruments requires removal of one followed by insertion of the other which results in additional trauma to the surrounding ocular tissue during the surgical operation as well as requiring additional items for each surgical procedure with the attendant sterilization, cleanliness and assembly requirements.
These techniques are also applicable to endocapsular cataract extraction wherein the capsular bag is left relatively intact and the irrigation/aspiration tip is introduced via a small limbal incision and a small anterior capsulotomy.
In response to these deficiencies in prior art instruments, a need has developed to provide a single surgical instrument which permits access to difficult to reach areas while still performing a desired surgical procedure such as aspiration of cortex or other lenticular material during a cataract extraction operation.
In response to this need, the present invention provides a flexible and steerable aspiration tip for microsurgery, in particular, ophthalmic surgery such as cataract removal. The flexible and steerable aspiration tip of the present invention includes a flexible tip portion, the shape of which may be remotely altered to permit the tip portion to access difficult to reach areas. The flexible and steerable aspiration tip permits performing a variety of surgical procedures while eliminating the requirement of using differently configured tips during the surgical procedure.
None of the prior art cited above teaches or fairly suggests a flexible and steerable aspiration tip including means to remotely position the flexible tip portion to access hard to reach areas.